Genome-wide analysis of pluripotency marker expression of ESKM-iPS cells
ABSTRACT: iPS cells, produced in in presence of exogeneously expressed E-cadherin and abcence of viral Oct4 were compared with conventional produced OSKM-iPS cells and murine embryonic stem cells (mESCs) or MEFs Overall design: Total RNA was isolated from iPSCs and mESCs grown in presence of LIF on gelatin-coated plates for 4 days and from murine embryonic fibroblasts grown in standard medium (DMEM-Glutamax, high-glucose, 10 % FBS, 1X non-essential amino acids, penicillin/ streptomycin
Project description:iPS cells, produced in in presence of exogeneously expressed E-cadherin and abcence of viral Oct4 were compared with conventional produced OSKM-iPS cells and murine embryonic stem cells (mESCs) or MEFs Total RNA was isolated from iPSCs and mESCs grown in presence of LIF on gelatin-coated plates for 4 days and from murine embryonic fibroblasts grown in standard medium (DMEM-Glutamax, high-glucose, 10 % FBS, 1X non-essential amino acids, penicillin/ streptomycin
Project description:Induced pluripotent stem cells (iPSCs) are commonly generated by transduction of Oct4, Sox2, Klf4 and Myc (OSKM) into somatic cells. Though iPSCs are pluripotent, they frequently exhibit high variation in their quality as measured by chimera contribution and tetraploid (4n) complementation. Thus, improving the quality of iPSCs is an indispensable prerequisite for future iPSC-based therapy. Here we show that one major determinant for iPSCs quality is the selection of the reprogramming factors combination. Ectopic expression of Sall4, Nanog, Esrrb and Lin28 (SNEL) in MEFs efficiently generated high quality iPSCs as compared to other combinations of factors. SNEL-iPSCs produced approximately 5 times more efficiently “all-iPSC” mice compared to OSKM-iPSCs. While differentially methylated regions, transcript number of master regulators, establishment of ESC-specific super enhancers, and global aneuploidy were comparable between the lines, aberrant expression of 1,765 genes, trisomy of chromosome 8 and abnormal H2A.X deposition were frequently observed in poor quality OSKM-iPSCs. For high-quality iPSCs, H2A.X pattern of SNEL is most similar to that of ESC, OSK and OSKM have more devoid regions than SNEL iPSCs. Compare H2A.X deposition pattern of the OSKM 4-factor iPS cell lines (4N-), SNEL 4-factor iPS cell lines (4N+) with ChIP-Seq. The same background ES cell line as the control line.
Project description:Coordinate expression of the somatic cell reprogramming factors Oct4, Sox2, Klf4 and c-Myc within embryonic stem cells preserves the self-renewal of these cells, while allowing for the expression epitope tagged Sox2. Taking advantage of this observation, we engineered embryonic stem cells (i-OSKM-ESC) to inducibly express Oct4, Klf4, c-Myc and an epitope tagged form of Sox2 from a polycistronic element, in the presence of doxycycline. We isolated Sox2 and its associated protein complexes by co-immunoprecipitation. Subsequently, we identified the Sox2-protein interactome in self-renewing embryonic stem cells using an unbiased proteomic screen (Multidimensional Protein Identification Technology [MudPIT]). Affymetrix microarrays were used to characterize the gene expression profile of i-OSKM-ESC in the absence and presence of doxycycline. Mouse embryonic stem cells (KH2) were engineered to express Oct4, epitope tagged Sox2, Klf4 and c-Myc in the presence of doxycyline, to produce i-OSKM-ESC. The i-OSKM-ESC were cultured in the absence or presence of doxycyline (4 µg/mL) for 24 hours. RNA was extracted from each condition, and used for microarray analysis.
Project description:Polycomb group (PcG) proteins comprise a large group of evolutionary conserved factors with essential roles for embryonic development and adult stem cell function. PcG proteins constitute two main multiprotein polycomb repressive complexes (PRC1 and PRC2) that operate in a hierarchical manner to silence gene expression. Functionally distinct PRC1 complexes are defined by Polycomb group RING finger protein (PCGF) paralogs. So far, six PCGF paralogs (PCGF1-6) have been identified but paralog-specific functions are not well understood. In our studies, we observed that Pcgf6 showed the highest expression level in undifferentiated murine embryonic stem cells (ESCs), blastocysts and testes. When ESCs differentiated, Pcgf6 expression strongly declined. To further investigate Pcgf6 biology, we established dox-inducible shRNA knockdown (KD) ESCs. Following Pcgf6 KD in ESCs the expression of pluripotency genes decreased, while mesodermal- and spermatogenesis-specific genes were de-repressed. Concomitantly with the elevated expression of mesodermal lineage markers, Pcgf6 KD ESCs showed increased hemangioblastic and hematopoietic activities. Finally, PCGF6 replaced SOX2 but not KLF4 or c-MYC in the generation of germline-competent iPS cells. Forced expression of Pcgf6 in OSKM-driven reprogramming increases iPS efficiency while Pcgf6 KD reduces the formation of ESC-like colonies. Together, these analyses show that Pcgf6 is non-redundantly involved in maintaining the pluripotent nature of ESCs and functions in iPS reprogramming. 6 samples were hybridized GeneChip Mouse Gene 1.0 ST Arrays (Affymetrix)
Project description:The generation of induced pluripotent stem (iPS) cells holds great promise in regenerative medicine. However, the relative flaws in the understanding of the molecular mechanisms promoting or limiting reprogramming still hinder the efficient generation of high quality iPS cells. Whereas modulation of the initial Oct4, Sox2, Klf4 and c-Myc (OSKM) cocktail with new transcription factors has been extensively documented, comparatively little is known about soluble molecules promoting the process, even if such recombinant factors could be highly valuable for therapeutic applications. In this study we developed a large-scale identification method to uncover novel programmed cell death (PCD)-related mechanisms limiting somatic cell reprogramming to pluripotency (SCRP). We identified Netrin-1 and its dependence receptor Dcc (Deleted in Colorectal Carcinoma), previously described for their respective survival/death functions both in normal and oncogenic contexts, as novel key SCRP modulators. We show that the early phase of SCRP is accompanied with a strong Netrin-1 deficiency, due to the improper epigenetic regulation of the Ntn1 promoter by OSKM. Mechanistically, we demonstrate that such Netrin-1 imbalance induces apoptosis mediated by the dependence receptor Dcc in a p53-independent manner. Correction of the Netrin-1/Dcc equilibrium by gain-of-ligand and loss-of-receptor experiments constrains apoptosis and improves reprogramming. As a consequence, we propose a novel iPS derivation protocol including a sequential treatment with recombinant Netrin1 that greatly facilitates the generation of mouse and human iPS cells. RNA-sequencing of mouse embryonic fibroblasts (passage 2 and passage 4), mouse pre-iPS cells (passage 5 and passage 25), 1 clone of control iPS (passage 5 and passage 25) and 2 independent clones of "Netrin-1 derived" iPS cells (passage 5 and passage 25). For this analysis, mouse iPS cell lines were grown in KSR+LIF media.
Project description:mESCs treated with retinoic acid (RA) and a Shh agonist (SAG) recapitulated ventral hindbrain development and produced a population of neural progenitors with a minor presence of other cell types. Overall design: The differentiation in mESCs was induced by RA and SAG in monolayer condition. The cells were collected every day and processed for RNA isolation and RNA-seq.
Project description:Nonsense-mediated mRNA decay (NMD) is a conserved RNA surveillance pathway that is an important modulator of disease pathology and is required for embryonic development. Despite significant research effort, the rules that govern NMD remain incompletely understood. Here we used a combined¬ approach, integrating RNA-Seq, ribosome footprinting, and CLIP-Seq analysis of the essential NMD factor Upf1, to provide a more complete picture of the role of NMD in modulating gene expression in murine embryonic stem cells (mESCs). We show that presence of an exon-exon junction ≥50 nucleotides (nt) downstream of a termination codon (dEJ) contributes to NMD independently of 3' UTR length, but has stronger effects in genes with shorter 3' UTRs. We also map translated upstream open reading frames (uORFs) in mESCs and show that they are associated with NMD regulation, especially of genes encoding transcription factors, and we find that lowly translated mRNAs can escape NMD. Finally, we identify over 200 direct binding targets of Upf1 and describe a pathway of Upf1-dependent gene regulation reliant on Upf1 binding to the 3' UTR and independent of presence of a dEJ. Together, these analyses characterize known and discover novel determinants of NMD and establish a broader role in mESC gene regulation for Upf1. mRNA-Seq analysis of wildtype (2 samples), translationally inhibited (by cycloheximide treatment, 2 samples), control-depleted (2 samples), and Upf1-depleted (4 samples) mouse embryonic stem cells (mESCs); CLIP-Seq analysis of Upf1 (5 samples, and 5 samples of IgG control CLIP-Seq); Ribosome footprint profiling of wildtype (1 sample), control-depleted (1 sample), and Upf1-depleted (1 sample) mESCs
Project description:Nanog null neural stem (NS) cells were reprogrammed to naive pluripotency in 2i/LIF conditions with mouse (m) Nanog and human (h) Nanog. Global gene expression in resulting iPS cells was compared to embryonic stem (ES) cells and nanog null NS cells. Murine iPS cells derived with mouse nanog iPS and human nanog iPS and then compared to embryonic stem cells and nanog null neural stem cells (3 replicates each).
Project description:Alveolar epithelial type II (ATII)-like cells can be generated from murine embryonic stem cells (ESCs), although to date, no robust protocols applying specific differentiation factors are established. We hypothesized that the keratinocyte growth factor (KGF), an important mediator of lung organogenesis and primary ATII cell maturation and proliferation, together with dexamethasone, 8-bromoadenosine-cAMP, and isobutylmethylxanthine (DCI), which induce maturation of primary fetal ATII cells, also support the alveolar differentiation of murine ESCs. Here we demonstrate that the above stimuli synergistically potentiate the alveolar differentiation of ESCs as indicated by increased expression of the surfactant proteins (SP-) C and SP-B. This effect is most profound if KGF is supplied not only in the late stage, but at least also during the intermediate stage of differentiation. Our results indicate that KGF most likely does not enhance the generation of (mes)endodermal or NK2 homeobox 1 (Nkx2.1) expressing progenitor cells but rather, supported by DCI, accelerates further differentiation/maturation of respiratory progeny in the intermediate phase and maturation/proliferation of emerging ATII cells in the late stage of differentiation. Ultrastructural analyses confirmed the presence of ATII-like cells with intracellular composite and lamellar bodies. Finally, induced pluripotent stem cells (iPSCs) were generated from transgenic mice with ATII cell-specific lacZ reporter expression. Again, KGF and DCI synergistically increased SP-C and SP-B expression in iPSC cultures, and lacZ expressing ATII-like cells developed. In conclusion, ATII cell-specific reporter expression enabled the first reliable proof for the generation of murine iPSC-derived ATII cells. In addition, we have shown KGF and DCI to synergistically support the generation of ATII-like cells from ESCs and iPSCs. Combined application of these factors will facilitate more efficient generation of stem cell-derived ATII cells for future basic research and potential therapeutic application. 10 samples in total. mESCs at d8 of differentiation (Control) mESCs at d8 of differentiation with KGF treatment mESCs at d17 of differentiation (Control) mESCs at d17 of differentiation with KGF treatment mESCs at d17 of differentiation with DCI treatment mESCs at d17 of differentiation with KGF and DCI treatment mESCs at d24 of differentiation (Control) mESCs at d24 of differentiation with KGF treatment mESCs at d24 of differentiation with DCI treatment mESCs at d24 of differentiation with KGF and DCI treatment
Project description:SETD2/HYPB has been known as a histone H3K36 specific methyltransferase. However, its roles in physiology such as development and cellular function remain unclear. In this study, using mESCs as cellular model, we show that Setd2 mainly regulates differentiation of murine embryonic stem cells (mESCs) towards primitive endoderm. This study aimed at exploring how did Setd2 regulate primitive endoderm. differentiation. We used microarrays to detail the global programme of gene expression controled by setd2, which is required for endoderm differentiation. Wild type and Setd2 knockout mESCs were selected for RNA extraction and hybridization on Affymetrix GeneChip® mouse genome 430 2.0 arrays. We sought to obtain some deregulated genes, which were required for primitive endoderm differentiation. For comparison, three biological repeats of each were performed.